Diverse adolescents’ transcendent thinking predicts young adult psychosocial outcomes via brain network development

Developmental scientists have long described mid-adolescents’ emerging capacities to make deep meaning about the social world and self, here called transcendent thinking, as a hallmark developmental stage. In this 5-years longitudinal study, sixty-five 14–18 years-old youths’ proclivities to grapple psychologically with the ethical, systems-level and personal implications of social stories, predicted future increases in the coordination of two key brain networks: the default-mode network, involved in reflective, autobiographical and free-form thinking, and the executive control network, involved in effortful, focused thinking; findings were independent of IQ, ethnicity, and socioeconomic background. This neural development predicted late-adolescent identity development, which predicted young-adult self-liking and relationship satisfaction, in a developmental cascade. The findings reveal a novel predictor of mid-adolescents’ neural development, and suggest the importance of attending to adolescents’ proclivities to engage agentically with complex perspectives and emotions on the social and personal relevance of issues, such as through civically minded educational approaches.


Head Motion and Cardiac Pulsation
The following analyses were conducted to confirm that our findings could not be attributed to head motion or cardiac pulsation: A. Relationships between head motion measures (number of volumes with framewise C. As a final confirmatory analysis, we additionally accounted for the variability related to cardiac pulsation.Pulse waveform peaks were identified using the Acqknowledge software (version 4.1; BIOPAC Systems Inc., Goleta, CA, USA) and visually inspected.Misidentified peaks were manually corrected.The resulting pulse peak timing information was processed using the Translational Algorithms for Psychiatry-Advancing Science (TAPAS) toolbox 1 (Version 6.0.1) to calculate cardiac RETROICOR regressors 2 .This method models cardiac-related physiological noise as a low-order Fourier expansion (model order = 3, for 6 terms) of the cardiac phases.
We recalculated the internetwork connectivity scores accounting for the 6 cardiac regressors and the 24 terms associated with head motion.Using these new scores, all models in the manuscript hold: Adolescents' transcendent construal scores predicted the increase in connectivity between the DMN and the left ECN components across the two-year interval following the interview, controlling for differences in head motion between the two neuroimaging data collections and time between data collections (b = 0.007, SE = 0.003, t[55.2]= 2.75, p = 0.008; bootstrapped 95% CI [0.003, 0.012]).For the developmental cascade, the complete path is significant (effect through the complete path = 0.005, bootstrapped 95% CI [0.0006, 0.0110]), while alternative paths that omit either or both of the intermediate measures are not.

Evaluating Network Component Maps.
The IC's identified in our analysis are very similar to the templates derived from large-

Verifying the Path Model with Complete Cases.
We calculated the effects of each of the four paths tested with relation to Hypothesis 2 in the main manuscript, with only the complete cases included (i.e., participants with any missing data were excluded; n = 44 included).Effect through the complete path holds: estimated effect = 0.007, bootstrapped SE = 0.004, bootstrapped 95% CI [0.001, 0.018].Alternate paths omitting developmental measures do not hold, just as is the case for the analysis presented in the main manuscript.
displacement [FD] exceeding 1mm; average FD) and transcendent construal scores were examined in the data collected at each timepoint separately, and on the intraindividual change in motion between timepoints; all p's > 0.42.B. ICA analysis was repeated using the portion of the sample (n = 27) with lowest head motion, as a stringent data scrubbing procedure.Across participants and across the two data collections: the number of volumes across the scan with FD over 1 mm ranged from 0 to 5 out of 210 (M = 0.6, SD = 1.3); the average FD across the resting state scan ranged from 0.07 to 0.24 mm (M = 0.13, SD = 0.04).The relationship between transcendent construal scores and change in network connectivity between DMN and left ECN holds in this portion of the sample (b = 0.01, SE = 0.004, t[23] = 3.31, p = 0.003), controlling for differences in head motion between the two neuroimaging data collections and time between data collections.Additionally controlling for age, sex, IQ, SES, and starting level of connectivity between these components (i.e., all covariates), the relationship between transcendent construal scores and change in network connectivity between DMN and left ECN remains significant, b = 0.008, SE = 0.003, t[17] = 2.69, p = 0.02.

Figure S2 .
Figure S2.Time courses (A), power spectrum density plots (B), and spatial maps (C) for select